This study was conducted to find sensitive indicator of food intake and specific food group related to cognitive function and to analyze the pathway among factors affecting food intake and cognitive function of the aged. 179 people over 50 years old were investigated and all the data were analyzed by SPSS 10.0 package. Food frequency was more sensitive indicator to show the relationship between food intake and cognitive function of the aged than the numbers of standard amount of food eaten. Consumption of grains and starch, meat, fish, eggs and beans were strongly related to cognitive function of the aged and intake of vegetables and fruits also have relationship with it. Moreover, the more frequent eating the carbohydrate and the protein, the higher the cognitive level of the aged. Age, education period, income, blood pressure, duration after retirement, frequency of physical activity and BMI were correlated with food intake and cognitive function of the aged. Among them, age and frequency of physical activity were most strongly correlated with food intake, and education period with cognitive function of them. This investigation shows that more stable intake of carbohydrate and protein containing foods need to be supplied to low income aged and the importance of physical activity of the aged must be emphasized with food intake for better life of the aged.